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Maseeh Colloquium: The Essential Role of Phase Delayed Inhibition in Decoding Synchronized Oscillations within the Brain
Friday, January 10, 2014 - 3:15pm

The Maseeh Mathematics and Statistics Colloquium Series*
presents

The Essential Role of Phase Delayed Inhibition in Decoding Synchronized Oscillations within the Brain
by Mainak Patel, Ph.D., Duke University, Department of Mathematics

Friday, January 10th, 2014 at 3:15pm
Neuberger Hall room 454
(Refreshments served at 3:00 in presentation room
This event is free and open to the public 

Abstract:
The widespread presence of synchronized neuronal oscillations within

the brain suggests that a mechanism must exist that is capable of
decoding such activity.  Two realistic designs for such a decoder
include: 1) a read-out neuron with a high spike threshold, or 2) a
phase-delayed inhibition network motif. Despite requiring a more
elaborate network architecture, phase-delayed inhibition has been
observed in multiple systems, suggesting that it may provide inherent
advantages over simply imposing a high spike threshold. We use a
computational and mathematical approach to investigate the efficacy of
the phase-delayed inhibition motif in detecting synchronized
oscillations.  We show that phase-delayed inhibition is capable of
creating a synchrony detector with sharp synchrony filtering
properties that depend critically on the time course of inputs.
Additionally, we show that phase-delayed inhibition creates a
synchrony filter that detects synchrony far more robustly than that
created by a high spike threshold. A high spike threshold detects a
minimum number of synchronous input spikes (absolute synchrony), while
phase-delayed inhibition requires a fixed fraction of incoming spikes
to be synchronous (relative synchrony).  Furthermore, we show that, in
a system with noisy encoders where stimuli are encoded through
synchrony, phase-delayed inhibition enables the creation of a decoder
that can respond both reliably and specifically to a stimulus, while a
high spike threshold does not.

* Sponsored by the Maseeh Mathematics and Statistics Colloquium Series
Fund and the Fariborz Maseeh Department of Mathematics & Statistics,
PSU.